emacs: move propagatedUserEnvPkgs from externalSrc to fix-rtags

It is weird to modify propagatedUserEnvPkgs in externalSrc.

The only changed package of this patch is emacs.pkgs.evil-ghostel,
which is intended.

pkgs/applications/editors/emacs/elisp-packages/lib-override-helper.nix

@@ -32,12 +32,17 @@ rec {
 
   externalSrc =
     pkg: epkg:
-    pkg.overrideAttrs (previousAttrs: {
+    pkg.overrideAttrs {
       inherit (epkg) src version;
-      propagatedUserEnvPkgs = previousAttrs.propagatedUserEnvPkgs or [ ] ++ [ epkg ];
-    });
+    };
 
-  fix-rtags = pkg: dontConfigure (externalSrc pkg pkgs.rtags);
+  fix-rtags =
+    pkg:
+    dontConfigure (
+      (externalSrc pkg pkgs.rtags).overrideAttrs (previousAttrs: {
+        propagatedUserEnvPkgs = previousAttrs.propagatedUserEnvPkgs or [ ] ++ [ pkgs.rtags ];
+      })
+    );
 
   fixRequireHelmCore =
     pkg:

pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix

@@ -289,6 +289,9 @@ let
           # Build same version as Haskell package
           hindent = (externalSrc super.hindent pkgs.haskellPackages.hindent).overrideAttrs (attrs: {
             packageRequires = [ self.haskell-mode ];
+            propagatedUserEnvPkgs = attrs.propagatedUserEnvPkgs or [ ] ++ [
+              pkgs.haskellPackages.hindent
+            ];
           });
 
           hotfuzz = super.hotfuzz.overrideAttrs (old: {